You guys! I can't believe you've fallen for such an obvious piece of image manipulation! "Get A BRAIN! MORANS" and "Go USA" is not what the guy's signs were originally saying, they've been photoshopped. Here's the original, untouched picture:

The man is actually protesting against the disrespectful parody of Darth Vader in Spaceballs. And "OSA" stands for "Organized Starwarsfans of America".

For a perfect example, just look at one of the greatest teams ever assembled: the 2006 World Champion St. Louis Cardinals. That team had David Eckstein, Yadier Molina, So Taguchi, and Aaron Miles. That's a Jew [sic], a Mexican [sic], a Chinaman [sic], and a regular American. It was a variable [sic] "League of Nations" of doing the little things. They hustled like all get out, they bunted all the time, and they weren't afraid to move the runner over. And most important, they got it done in the clubhouse, by which I mean, they created something I refer to as "a winning atmosphere."

Archie: What’s the matter with this? I call this representative government. You’ve got Salvatori, Feldman, O’Reilly, Nelson–that’s an Italian, a Jew, an Irishman and a regular American there. That’s what I call a balanced ticket.

Jacques Moran, second narrator and seeker of the eponymous Molloy in the novel by Samuel Beckett Lucy Moran, character in Twin Peaks Michael Moran, the central character in John McGahern's novel Amongst Women Moran, a female Irish Quidditch player in Harry Potter and the Goblet of Fire Sebastian Moran, the villain from the Sherlock Holmes short story "The Adventure of the Empty House" Summer Moran, a recurring character in Clive Cussler's novels featuring Dirk Pitt Mullin Shetland, a character in the anime series Last Exile, whose original Japanese name is Moran Shetorando